1. March 9, 2011
High Energy Physics 101
Kihyeon Cho

2. People have long asked, What is world made of? and
What holds it together?

3. What is world made of?
In Ancient time
fire
earth
water
air

4. What is World Made of?

5. Standard Model t, b, c are heavier than other quarks
- heavy flavor quarks
W, Z, top are stand out from the rest.

6. Matter Hadron (Quark) - size Lepton – no size
Baryon (qqq): proton, neutron
Meson (q qbar): pion, kaon
Lepton – no size
Point particle

7. How to know any of this? (Testing Theory)
Example
Light bulb (Source)
Tennis ball (target)
Eye (detector)

8. How to detect? Accelerators solve two problems:
High energy gives small wavelength to detect small particles. (Lambda = h /p )
The high energy create the massive particles that the physicist want to study.(E=mc^2)

9. Accelerator design Shapes Collision types Linacs (SLAC)
Synchrotrons (Fermilab)
Collision types
Fixed target (E687, FOCUS)
Colliding beams (CDF, Belle, BTeV)
=> CM = 1TeV+1TeV => 2TeV

10. High Energy Experiment

11. Fixed target vs Colliding beams
(total energy)2-(total momentum)2 = invariant in all frames of reference
Assume that 800GeV(Ebeam) proton collides in a fixed target(proton).
Center of mom. frame Laboraroty frame
Total energy: ECM Ebeam+mp
Total momentum: Pbeam
Invariant: ECM (Ebeam+mp )2-Pbeam2
E = [ 2(mp2+Ebeammp) ]1/2 = 38.8GeV
We are enough to 19.4GeV+19.4GeV proton beams in collider !!!
Question: What’s the advantage of a fixed target experiment?

12. Experiments related to CKM parameters
e+e- B Factories
Major experiments ongoing, some ended
Talk by Elisabetta Barberio

13. 전자-양전자 충돌 가속기 실험
This plot shows the current heavy flavor physics experiments by electron and positron. BESII, CLEOc, Belle, BaBar.
They has excellent photon resolution.

14. Belle II (2014~)
The next thing is superbelle.

15. 양성자-양성자 충돌 가속기 실험 (Large Hadron Collider)
CERN
LHCb
ATLAS
Let me talk about LHC Experiment. There are 4 big experiments at LHC which are
CMS, ATLAS and LHCb.
CMS
ALICE
LHC at CERN

16. 양성자-반양성자 충돌 가속기 실험 (Tevatron)
This plot shows the current heavy flavor physics experiments by electron and positron. CDF and D0.
Heavier B => Full Service of B factory